懂你英语level 3 unit.docx

懂你英语level 3 unit.docx

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懂你英语level3unit

Level3unit1part1

Listening

Matterismadeofatomsandmolecules.

Water,forexample,istheH2Omolecule.

Thismeansthatamoleculeofwaterhas3atoms.

Awatermoleculehas2hydrogenatomsandoneoxygenatom.

Substanceslikesugarhavemanyatomsintheirmolecules.

Amoleculeofsugarhasmanyatoms,includingcarbine,hydrogenandoxygen.

-WhatisH2O?

Thewatermolecule.

-Whatismattermadeof?

-

Atomsandmolecules

MatterismadeofmoleculessuchastheH2Owhichisthewatermolecule.

Mattercanbeinoneof3states,solid,liquidorgas.

Waterandicearethesamesubstance,buttheyareindifferentstates.

Thesestatesdependonthetemperatureofthemolecules.

Whenweheatasubstance,themoleculesmovefasterandtrytotakeupmorespace.

Whenwecoolasubstance,themoleculesmovemoreslowly.

Whenwecoolasubstancetoitsfreezingpoint,itbecomesasolid.

-Howmanystatesofmatterarethere?

-

Three.-

-Whathappenswhenweheatasubstance?

themoleculesmovefasterandtrytotakeupmorespace.

-Whathappensifwecoolaliquidtoitsfreezingpoint?

Itbecomesasolid.

Inasolid,themoleculesmoveverylittle.

Theirpositionsarealmostfixed.

Tobefixedmeansthattheirpositionsdontchange.

Ifweheatthemolecules,theymovefasterandawayfromeachother.

Thesolidbeginstomelt,likeicecreamonahotday.

-Howcanwechangeasolidintoaliquid?

heatitup.

-Howcanwechangealiquidintoasolid?

coolitdown.-

Atacertaintemperature,asolidbeginstochangeintoaliquid.

Thetemperatureatwhichasolidchangesintoaliquiddependsonthesubstances.

Forwater,thesolidbeginstochangeintoaliquidwhenitstemperaturerisestoabove0degreesCelsius.

Forsomesubstances,suchassteel,thetemperatureatwhichitbecomesaliquidismuchhigher.

Steeloftenmeltsataround1370degreesCelsius.

-Atwhattemperaturedoesicebegintomelt?

Above0degreeCelsius.

-Whatdoesthetemperatureatwhichasubstancebeginstomeltdependon?

Thesubstances.

Ifwecontinuetoheataliquid,themoleculesmoveevenfaster.

Atacertaintemperature,theliquidbeginstochangeintoagas.

Forwater,theliquidbeginstochangeintoagasat100degreesCelsius.

Thatistheboilingpointofwater.

-Whathappensifwecontinuetoheataliquid?

Moleculesmoveevenfaster.

Insideastar,suchasoursun,thetemperatureisveryhigh.

Everythinginsidethesunisagas.

Accordingtoscientists,thereareover65elementsinsidethesun.

Theseincludeoxygenandiron.

Over90%ofthesunishydrogengas.

-Howmanyelementsareinsidethesun?

Morethan65

Yesterday,therewasanimportantsciencetest.

Lisa,Tomand20otherclassmatestookthetest.

Thetestisaboutthestatesofmatterandhowtheyaredifferent.

Therewere25questionsonthetextandtherehad45minutestotakeit.

Herearesomeofthetestresult.

2studentsgotperfectscores.

Thelowestscorewas68outof100.

Theaveragescorewas86.3.

11studentsscorehigherthanaverage.

11studentshavebelowtheaveragescores.

Tommissed2questiononthetestsohisscorewas92.

Hisscorewas8highestintheclass.

Lisamissed2andahalfquestionsoherscoreis90.

Herscoreis10highestscore.

Herscoreis4pointshigherthantheaveragescore.

Lisawasdisappointedwithhertestresults.

Shestudiedhardforthetestbutshestilldidntdowell.

Asaresult,sheplanstostudyharderfornexttest.

Thenexttestwillbeinabout2weeks.

Tomwassurprisedandhappywithhisresults.

Hedidntstudyhardsohisresultwasbetterthanheexpected.

HewasalsohappythathedidbetterthanLisadid.

Vocabulary

Sheisscreamingbecausesheisreallyscared.

Somethingischasinghersosheisscreamingforhelp.

Heisshoutingbecauseheisangry.

Whenhesreallyangryheoftenshoutslikethis.

Sheissleepingbecauseshestired.

Lastnightshedidntgetenoughsleep,sotodayshehasnoenergy.

Shescryingbecauseshessad.

Shegotsomebadnewsafewminutesago.

Shessmilingbecausesheshappy.

Herboyfriendjustcalledandhesreturningfromalongtrip.

Whoissmilingbecauseshegotsomegoodnews?

Thismanishikingupamountaintrail.

Heiswearinghikingbootsandiscarryingapackonhisback.

Thismanenjoyscooking.

Heattendsacookingclassonceaweek.

Thiswomanenjoysgardening.

Shegrowsflowers,suchasroses,andvegetables,suchastomatoes,inhergarden.

Thisboylovesplayinggames.

Helikesallkindsofgames,includingthisvideogamesonhiscomputer.

Thisoldcoupleenjoystravelling.

Theytakeseveraltripsayear,oftentodifferentcountries

Dialogue

W:

Oh,thereyouare,finally.

M:

Yeah,Imsorry.

W:

Whyareyousolate?

Youweresupposedtobehere30